js: Fix js.Batch for multihost setups

Note that this is an unreleased feature.

Fixes #13151

internal/js/esbuild/batch_integration_test.go

@@ -184,6 +184,69 @@ func TestBatchEditScriptParam(t *testing.T) {
 	b.AssertFileContent("public/mybatch/mygroup.js", "param-p1-main-edited")
 }
 
+func TestBatchMultiHost(t *testing.T) {
+	files := `
+-- hugo.toml --
+disableKinds = ["taxonomy", "term", "section"]
+[languages]
+[languages.en]
+weight = 1
+baseURL = "https://example.com/en"
+[languages.fr]
+weight = 2
+baseURL = "https://example.com/fr"
+disableLiveReload = true
+-- assets/js/styles.css --
+body {
+	background-color: red;
+}
+-- assets/js/main.js --
+import * as foo from 'mylib';
+console.log("Hello, Main!");
+-- assets/js/runner.js --
+console.log("Hello, Runner!");
+-- node_modules/mylib/index.js --
+console.log("Hello, My Lib!");
+-- layouts/index.html --
+Home.
+{{ $batch := (js.Batch "mybatch") }}
+ {{ with $batch.Config }}
+	{{ .SetOptions (dict 
+		"params" (dict "id" "config")
+		"sourceMap" ""
+		)
+	}}
+{{ end }}
+{{ with (templates.Defer (dict "key" "global")) }}
+Defer:
+{{ $batch := (js.Batch "mybatch") }}
+{{ range $k, $v := $batch.Build.Groups }}
+	{{ range $kk, $vv := . -}}
+		{{ $k }}: {{ .RelPermalink }}
+	{{ end }}
+{{ end -}}
+{{ end }}
+{{ $batch := (js.Batch "mybatch") }}
+{{ with $batch.Group "mygroup" }}
+ 	{{ with .Runner "run" }}
+		{{ .SetOptions (dict "resource" (resources.Get "js/runner.js")) }}
+	{{ end }}
+	{{ with .Script "main" }}
+		{{ .SetOptions (dict "resource" (resources.Get "js/main.js") "params" (dict "p1" "param-p1-main" )) }}
+	{{ end }}
+	{{ with .Instance "main" "i1" }}
+		{{ .SetOptions (dict "params" (dict "title" "Instance 1")) }}
+	{{ end }}
+{{ end }}
+
+
+`
+	b := hugolib.Test(t, files, hugolib.TestOptWithOSFs())
+	b.AssertPublishDir(
+		"en/mybatch/chunk-TOZKWCDE.js", "en/mybatch/mygroup.js ",
+		"fr/mybatch/mygroup.js", "fr/mybatch/chunk-TOZKWCDE.js")
+}
+
 func TestBatchRenameBundledScript(t *testing.T) {
 	files := jsBatchFilesTemplate
 	b := hugolib.TestRunning(t, files, hugolib.TestOptWithOSFs())